What does the expression "have a good head on your shoulders" mean?

Also, what sentence can you make about a head on your shoulder?

Have a solid head on your shoulders. to possess common sense, to be intelligent and sensible. Mary isn't a good student, but she has a strong head. John is a great listener and can give sound advice.

The question then becomes, "Do you have a good mind for matters of heart?" If someone says that you have a good mind for something, it means that you are naturally capable of doing something well. It is the same meaning that has a knack to do something. Use clever or smart if you are referring to someone who has intelligence and good judgment rather than a special talent.

Also, know that you have a good head meaning.

Have a good head for something. Kim is a natural talent to do things well.

What does the expression "Keep your head above water" mean?

Avoid financial trouble and keep your head above water. Also, be on top of work and other obligations. They are barely keeping their heads above the water or they have new bills every day, and I manage to keep my head above the water . This expression refers to avoiding drowning.